The present invention concerns a process for the production of a disintegrator roll of an open-end spinning apparatus, and a disintegrator roll manufactured by such a process.
DE 25 39 089 A1 discloses a disintegrating roll which has been equipped with a toothed active shredding-element, which displayed a substantial hardness in the top zone of the teeth, but in the foot zone a lesser hardness. In this way an ascertained winding of the toothed shredding-element on the body of the disintegrating roll could be assured. To this purpose, the point of each tooth is a separate element from the foot, and must be bound thereto, for example, by welding. This process is a very labor and time intensive procedure. For economic reasons, it cannot be allowed, that such a procedure can be a part of the manufacture of disintegrating rolls for open-end spinning apparatuses, since well over a hundred such rolls are required per open-end spinning machine.
In accord with another proposal offered by DE 29 04 841 A1, each tooth of the sawtooth shredding-element exhibits a plurality of zones of different hardness, whereby the hardness of the tooth diminishes in the direction from the tooth point to the foot. The tooth foot zone, contrarily, is not hardened, in order to allow for the necessary shaping of the sawtooth wire necessitated by the winding procedure. In order to be able to deform the ends of this sawtooth wire, so that the wire can be securely laid on the roll body, it is necessary to temper these wire ends after the hardening procedure, so that the hardening of the teeth will have no effect on wire ends. The disadvantage of this step is, that it is very difficult to restrict the hardening and subsequent heat treatment to specific areas.